Sewing machine



April 2-,- .1924.

- 1,490,928 .J. KIEWICZ SEWING MACHINE Filed D ec. 13. 19 2 2 heets-.Sheet 1.

\nvenTor.

2 John Kiewicg byiawwkfmmj Aflys.

April 22 ,.1924.

J. KIEWICZ SEWING MACHINE Filed Dec. '13 1922 Fig. 3.

2 Sheets-Sheet 2 lnvenTor.

John Kiewicg ATTys.

STATES PATENT OFFICE. I

sorta nrnwrca, or nosron, MASSACHUSETTS, Assienon TO THE nnncn rnrron stern MACHINE COMPANY, 0F BOSTON, MASSACHUSETTS, A CORPORATIONOF MAINE.

. snwrns MACHINE.

application died December 13, 1922. Serial No. 606,615.

To all whom it may concern:

Be it known that 1, JOHN Kmwioz, a citizen of the United States, and resident of Boston, county of Suffolk, State of Massachusetts, have invented an Improvement in Sewing Machines, oi which the following description, in connectionwith the accompanying drawing, is a specification, like characters on the drawing representing like parts. i

This invention relatesto sewing machines of the type including an upper needle for handling an upper thread, a looper situated beneath the work and adapted to take each loop of needle thread as the needle makes its penetrating thrust and an under needle operating beneath the work and controlling the under thread and adapted to a place loops thereof through the loops of the upper thread. In some sewing machines of this type the under needle is provided with two eyes, one situated near the point and the other situated in the shank of the needle a distance back from the point, the under thread passing through the last-named eye and. then extending along the side of the needle to the first eye from which it is delivered to the work, and the looper is arranged to reciprocate in a path closely adjacent the path in which the needle operates and on the side of the needle along which the thread passes from one eye to the other thereof. A sewing machine of this type is shown in Patent No. 1,188,942, June 27th, 1916..

In sewing machines such as illustrated in said patent the path of movement of the looper is so close to that of the needle that unless the under thread is kept taut there is danger that the looper will catch on the under thread at a point between the two eyes of the under needle. During the formation of the stitches the under thread is kept sufiiciently taut to avoid any interference between the looper and the under thread but during the formation of the first stitch at the beginning of any scam the under thread is not maintained under tension unless some means are provided for holding the end of the under thread while the first stitch is "formed. ltr" such thread-holding means is provided then there will be left an end of the under thread projecting from the work at thebeginning of the seam, this end representing the portion of the under thread which was retained by the holding means while the first stitch was formed. The production of such a projecting end of under thread is objectionable, especially in the formation of buttonholes because it necessitates the added operation of trimming 1su ih end in order to complete the buttontion of the first stitch then there will be no projecting end required to be trimmed after the buttonhole has been completed, but the under thread will not be maintained under tension and there is liability that the under thread will be sufficiently slack between the two eyes of the under needle so that it will catch on the looper and be withdrawn from the eye at the end of the needle thus dethreading the needle.

It is one of the objects of my present in- If on the other hand the end of the under thread is not held during the forma vention to provide an improved form of needle which is constructed to protect the thread between the eyes thereof so as to avoid any possibility that there will be interference between the thread and the looper in forming the first stitch even though the under thread is not held and may be somewhat slack. In the construction herein shown I accomplish this object by employing a needle which is tubular at the end so that the portion of the thread between the two eyes of the needle is enclosed in the tubular portion of the needle.

In order to give an understanding of the invention 1 have illustrated in the drawings a selected embodiment thereof which will now be described after which the novel features will be pointed out. in the appended claim.

. Fig. 1 is a fragmentary view of a sewing machine such as illustrated in said patent and showing the upper needle, under needle and looper;

Fig. 2 is a section on the line 2 2, Fig. 1;

Figs. 3 and i show the looperand the under needle having the construction now commonly used;

Fig. 5 is a similar view showing an under needle embodying the present invention;

Fig. 6 is a viewoi the under needle showing the opposite side thereof from that shown in Fig. 5.

Inasmuch as the present invention relates simply to the under needle for manipulating the under thread and its relation to the looper I have not thought it necessary to illustrate herein a complete sewing machine but have only shown a sufficient portion thereof to enable the present invention to be understood.

In the drawings 1 indicates a portion of the frame of a sewing machine of the type illustrated in said Patent No. 1,188,942 and 2 indicates the upper needle which reciprocates vertically and controls the upper thread 3 and 4 indicates the under needle which is situated beneath the work and which controls the under thread 5. 6 indicates the looper which engages the loop of upper thread after the upper needle 2 has made its penetrating thrust and holds said loop while the under needle 4 is carried through it.

In the construction herein shown the under needle 4 and the looper 6 are carried by a turret 7, which is rotatably mounted in the frame, said turret being provided with a throat plate 8 at its upper end through which the needle operates. The under needle 4 is a curved needle and is carried by a needle carrier 9 which is pivoted to the turret at 10 and the looper 6 having a threadengaging end 29 is carried by a rocking carrier 11 which is pivoted to the turret at 12 and which is provided with the cam slot 16 in which operates a roll 14 carried by a spindle 15 which reciprocates vertically in the turret.

The parts thus far described, with the exception of the under needle 4, are or may be all as usual in sewing machines of the type illustrated in said patent and as their operation is well known to those skilled in the art it is not deemed necessary to describe such operation in detail.

t may be said, however, that the under needle 4 moves upwardly in a curved path while the looper 6 moves back and forth horizontally and that the path in which the needle travels is closely adjacent to and crosses the path in which the thread-engaging end 29 of the looper travels. In prior constructions the under needle has had the construction shown in Figs. 3 and 4-wherein an under needle is indicated at 32 and is formed with two eyes 30 and 31, the eye 30 being situated at the end of the needle and the eye 31 being situated well back in the shank. This type of needle is threaded by passing the thread through the eye 31, then along the length of the needle and through the eye 30 at the end, the thread passing from said eye 30 to the work. This leaves a portion '33 of the thread exposed on the side of the needle which is adjacent the path of movement of the end 29 of the looper.

In the operation of the sewing machine the looper and under needle are so timed that as the under needle is rising to enter the loop of'upper thread the looper is being drawn laterally to spread said loop, the parts at this point in the cycle of operations having the relative movements indicated by the arrows in Figs. 3 and 4. The path in which the end 29 of the looper moves is so closely adjacent to the needle that unless the thread 5 is held taut the portion 33 thereof is apt to balloon slightly and thus come into the path of movement of the looper and thereby be caught by the latter. If this happens during the formation of the first stitch of the scam the engagement of the looper with the portion 33 of the thread is apt to draw the under thread out from the end eye 30 of the needle thus dethreading the latter as seen by dotted lines Fig. 4.

In order to avoid any such possibility I have provided an improved construction by which the portion 33 of the thread between the eyes of the needle is protected from any possible interference with the end 29 of the looper. In the construction illustrated this protection is afforded by making the needle so that it Will act as the protecting means' The needle illustrated has the tubular portion 20 at the end, said tubular portion providing a thread-receiving bore 17 through which the thread 5 passes. The needle is provided at one side with an eye or opening 18 leading into the bore at a point well back from the point of the needle and the needle is open at its end as shown at 19 to provide for the delivery of the thread from the bore 17. In threading up the needle the under thread 5 is inserted into the aperture 18 and then carried through the bore 17in the tubular portion 20 of the needle and extends out through the opening 19 of the needle.

The eye or entering opening 18 is situated a sufiicient distance from the end of the needle so that during the reciprocation of the needle said opening 18 is never carried above the path of movement of the looper and, therefore, the only portion of the needle which is at any time situated opposite the path of the looper 6 is the tubular portion of the needle through which the under thread 5 is extending. WVith this construction, therefore, the portion of the thread which is crossing the path of reciprocation of the looper is always enclosed within the tubular portion 20 of the needle and is, therefore, entirely protected from any possible engagement with the looper. With this construction of needle it is not necessary to provide any means for holding the end of the under thread 5 during the formation of the first stitch in order to keep the thread taut and thus free from the looper, for the under thread is protected from being caught on the looper by the tubular portion of the under needle and, therefore, there can be no neeaeee interference between the looper and the under thread even though the latter is somewhat slack.

In order to form the first stitch, therefore, it is simply necessary to havea suficient length of under thread drawn out from the end of the under needle to concatenate with the upper thread. The absence of any device for holding the end of the under thread in forming the first stitch is an advantage because it eliminates the formation of a thread end projecting from the seam which has to be subsequently trimmed. Where there is no thread-holding device then any projecting end of the under thread will be sewed into the seam during the formation of the stitch and no trimming operation is required.

ll claim:

lin a sewing machine, in combination, work-holding means, an upper needle carrying an upper thread and adapted to penetrate the work, a looper operating beneath the work to take the loop of needle thread thrown out from the needle at each penetrating thrust, means to actuate the looper, an

under needle adapted to penetrate the work from beneath and carrying an under thread, said under thread having a path of movement which crosses and is closely adjacent that of the looper, the portion oi the under needle which operates adjacent the path of the looper being tubular to receive the under thread and said needle having an eye intermediate of its length through which the under thread passes into the tubular portion and also having a delivery eye at its end through which the under thread leaves the tubular portion, said tubular portion protecting the under thread and preventing it from being caught on the looper.

In testimony whereof, I have signed my name to this specification.

JOHN KIEWICZ. 

